Posts Tagged ‘thermal’

I picked up a BD-D5700 back in Christmas 2011 on sale at Best Buy for $100. Cool – I can get a Blu-Ray player for $100! I’m in. It turned out to be $100 for a reason – it was dirt slow.

Finally, now in 2013 and fairly out of warranty, I cracked open the case. Inside, I found this.

The motherboard is about the size of a CD case, powered by a BCM7631 chip (Broadcom only has pages for BCM7630 and BCM7632 – weird). That powerful Broadcom SoC is cooled by one TINY layer of aluminum – barely as thick as a typical CPU’s heat spreader. Worse yet, the thermal compound was a pad, not even grease – leaving large burnt-out hot spots in the pad. The CPU is clearly overheating and thermal-throttling to prevent damage, and Samsung seems to have used that burn-out throttling to “class” the player as a cheap, slow device.

The heat needs to escape the chip quickly, and to do that, it needs somewhere to conduct to in a bubble area around the chip. In the current plate design, the top and center of the chip would get very hot very quickly, as there’s nowhere to conduct the heat to. We need a bigger heatsink.

The heat sink here is from a dead PC motherboard. The spacing between the pegs straddles two different positions on the Samsung board, so the two spring mechanisms need to have very different tensions. I accomplished this by using two different spring clips (note above) and weakening the spring on the white one. This ensures the heat sink will stay centered on the chip, so that a lever action doesn’t lift the corner off the chip.

Now, you need to clean and prep the board and the new heatsink. I use ArctiClean and Arctic Silver Ceramique 2. Your goal is to clean both surfaces until the only thing you see is the mirror of the chip and the grain of the metal (or, preferably, the mirror finish) of the heat sink.

A dob’ll do ya. Leave it beaded (careful about air pockets) so the heat sink will spread it evenly without trapping air.

As you assemble it, note how the heat sink rests flat on the chip.

And reassemble.

Done. Enjoy your player with a bit more pep in its step. Keeping that heat sink cool is key – now that it’s pulling away more of the heat from the chip and allowing it to run faster, it’ll produce more heat. Keep that in mind, and you’ll have a great player!